When open heart surgery is being performed, it is necessary to by-pass the blood from the heart through extracorporeal equipment which substitutes for the patient's heart and lung action during the operation. In this process, it is necessary to maintain or control the temperature of the blood as well as to move it in a manner which simulates the human heart.
It is preferable that the blood be moved though tubes and passages which provide as little mechanical disturbance as possible; and, accordingly, it is not desirable to utilize what is called an invasive temperature probe which is inserted into the blood itself.
The present invention, therefore, contemplates a non-invasive temperature probe which can monitor the temperature of the patient's blood during an operation in connection with the extracorporeal circulation.
Inasmuch as the temperature probe does not come into direct contact with the bloodstream, it does not need to be subjected to the rigors of the sterilization process, and this eliminates also the time and expense required for such sterilization. A disposable temperature transmitting tube can be interposed into a by-pass tube for contact with the reading device.